Effects of crowberry (Empetrum nigrum subsp. hermaphroditum) supplementation on inflammatory and metabolic adverse effects in high-fat diet-induced experimental obesity

Abstract

Background: Obesity continues to be a major global health challenge, often accompanied by chronic low-grade inflammation and metabolic complications, including insulin resistance, impaired glucose metabolism, dyslipidemia and non-alcoholic fatty liver disease (NAFLD). Diets enriched with plant-derived polyphenols have shown promise in alleviating inflammation and promoting a metabolically healthier obesity phenotype. Crowberry, a polyphenol-rich wild berry native to the boreal forest zone, is particularly abundant in anthocyanins. Here, we investigated the effects of crowberry supplementation on low-grade inflammation and metabolic disturbances in a mouse model of diet-induced obesity.

Design: Mice were fed for 12 weeks with low-fat or high-fat diet (10% or 46 % energy from fat, respectively), or with high-fat diet supplemented with crowberry powder. To ensure comparability, protein and micronutrient contents were standardized across all diets, and the two high-fat diets were matched for fat, carbohydrate, and fiber composition.

Results: Crowberry supplementation markedly suppressed the high-fat diet-induced elevations in serum amyloid A (SAA) and alanine aminotransferase (ALT), markers of systemic and hepatic inflammation, respectively. Additionally, crowberry supplemented diet attenuated the expression of multiple pro-inflammatory genes both in the liver and visceral adipose tissue. Overall body weight and visceral fat gain were not altered by crowberry suggesting direct health-promoting effects by crowberry constituent.

Conclusions: These findings demonstrate that crowberry supplementation can effectively counteract high-fat diet-induced systemic and hepatic inflammation in experimental obesity, supporting its use as a part of a healthy diet. Clinical studies are needed to assess the translation of these findings to humans and the role of crowberries in dietary strategies combating obesity and its comorbidities.